1. Field of the Invention
The present invention relates to an onboard display device that adequately displays a nightview image, a map image, and information-providing images such as an intersection guidance image and a display method for an onboard display device.
2. Description of the Related Art
In the field of display devices for vehicles that incorporate a nightview image display unit that displays a nightview image in front of the vehicle, the technology for identifying an obstacle present in front of the vehicle in the nightview image and displaying an image region including the obstacle on a large scale on the nightview image display unit when the obstacle has been identified, as described in Japanese Patent Application Publication No. 2007-159036 (JP-A-2007-159036).
However, although a nightview image is useful from the standpoint of enhancing the visibility for the driver in the nighttime, a comparatively expensive display (for example, a full-TFT display) has to be separately provided to display the nightview image. For example, in the configuration described in JP-A-2007-159036, a display at a meter is used, but the display incorporated in the meter has to be configured by a full-TFT display, thereby raising the display cost.
On the other hand, a display of a navigation device is intrinsically capable of high-performance displaying and also can display nightview images. Where the display of a navigation device is used in the aforementioned configuration to display the nightview images, a another display for displaying nightview images becomes unnecessary and the cost may be reduced. However, because a nightview image is displayed on the display of a navigation device in such a configuration, the display output from the navigation device is restricted and operability of the navigation device may be degraded.